Fuel cells are electrochemical systems which transform the chemical energy of the oxidation process directly into electrical energy. Their functional principle is similar to that of a primary Battery with the difference that the energy is not stored between the electrodes, but is instead transferred from an external tank. Fuel cell technology was actually invented more than 100 years ago. Today the technology is used for the production of electric and thermal energy in power-heat coupling systems (Block-Type Thermal Power Station (BTTP))and it is also the source of electricity in electric automobiles. Unlike battery-powered electric automobiles, fuel cell powered automobiles achieve similar ranges and load-carrying capacities to conventional automobiles with combustion engines. In the past few decades, significant advances in the materials sciences have helped spur the breakthrough of fuel cell technology.